| Liquid is one of the three forms of material existence, which is often an important object of research. In the field of ecological protection, food industry, health care, manufacturing and other industries, liquid is an essential factor, so it is imperative to use advanced science and technology to establish an accurate and practical mathematical model, to study various and effective analysis methods, and to make practical and precise instruments with effective detection of liquid. Traditional liquid detection technology is often operated in the laboratory, and needs to use various containers, analyzer and other kinds of equipment. What s more, the waiting time is relatively long for the volatile liquid. The longer measuring lasts, the more liquid ingredients will be evaporated, causing measurement results less accurate. How to detect the liquid quickly, accurately, conveniently and in real-time has become a research and development direction of the liquid drop analysis technology.Liquid drop analysis technology is a new test technology in recent years, which refers to the technology of monitoring liquid droplet formation process to obtain the physical and chemical parameters related to liquid under a certain external environment, and thus to realize the qualitative identification and quantitative measurement.The liquid drop analysis technology is combined with the optical fiber drop analysis method and the capacitive drop analysis method, which can obtain the light intensity signal and capacitance signal at different time in the liquid droplet's growth cycle., The light intensity signal and the capacitance signal are processed by the signal detection circuit, by the liquid drop data acquisition system, and then the liquid drop fingerprint can be obtained which reflects some physical and chemical properties of the liquid. When the external measurement environment is unchanged in some degree, each liquid has its own unique liquid drop fingerprint image, and the quantitative and qualitative identification of the liquid can be realized through the analysis of the liquid fingerprint.The main work of this paper includes:1. The optical fiber signal detection circuit and capacitance signal detection circuit as well as liquid drop sensor mechanical structure are designed, and the experimental setup of the liquid drop analysis system has been finished.2. Based on the hardware circuit and the software of the acquisition, the acquisition of optical fiber signal and capacitance signal is completed.3. Some liquid samples are analyzed, and some liquid properties are analyzed according to the liquid drop fingerprint.4. Based on droplet image analysis technique, image feature parameters are expanded, including new parameters for providing a new method for the drop analysis. |
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